mm: build_zonelists(): move clear node_load[] to __build_all_zonelists()
If node_load[] is cleared everytime build_zonelists() is
called,node_load[] will have no help to find the next node that should
appear in the given node's fallback list.
Because of the bug, zonelist's node_order is not calculated as expected.
This bug affects on big machine, which has asynmetric node distance.
[synmetric NUMA's node distance]
0 1 2
0 10 12 12
1 12 10 12
2 12 12 10
[asynmetric NUMA's node distance]
0 1 2
0 10 12 20
1 12 10 14
2 20 14 10
This (my bug) is very old but no one has reported this for a long time.
Maybe because the number of asynmetric NUMA is very small and they use
cpuset for customizing node memory allocation fallback.
[akpm@linux-foundation.org: fix CONFIG_NUMA=n build]
Signed-off-by: Bo Liu <bo-liu@hotmail.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index d052abb..5cc986e 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -2544,7 +2544,6 @@
prev_node = local_node;
nodes_clear(used_mask);
- memset(node_load, 0, sizeof(node_load));
memset(node_order, 0, sizeof(node_order));
j = 0;
@@ -2653,6 +2652,9 @@
{
int nid;
+#ifdef CONFIG_NUMA
+ memset(node_load, 0, sizeof(node_load));
+#endif
for_each_online_node(nid) {
pg_data_t *pgdat = NODE_DATA(nid);